Laser source device, image display device and monitor device having the same

Abstract

A laser light source device capable of high effectively restraining output light power decreasing, high light using rate, consistent polarization direction of the output light, and outputting stably, and an image display device with the laser light source device and a monitor device are provided in the present invention. The laser light source device (31) has: a light source (311), a wavelength changing element (312), an external resonance device (313) and a light changing element (314). The wavelength changing element (312) is arranged in the resonance structure, the second laser (LS2) is broken out according with a second light path (02) by the light path changing element (314), towards the approximately same direction with a first laser (LS1) advancing direction, it together with the first laser (LS1) are used as output light. Selective reflecting film (317) and reflecting face (316A) for taking out the second laser (LS2) are integrated by prisms (315, 316).

Description

technical field [0001] The present invention relates to a laser light source device that emits laser light, and an image display device and a monitor device including the laser light source device. Background technique [0002] In recent years, laser light source devices have been widely used in optoelectronic fields such as optical communication, optical application measurement, and optical display. [0003] As such a laser light source device, there are those that directly use the wavelength of the fundamental laser beam, and those that convert and use the wavelength of the fundamental laser beam. In the latter laser light source device, a second harmonic light generation (SHG: Second Harmonic Generation) element is known as an element that converts the wavelength of the fundamental laser beam. [0004] Here, since the conversion efficiency of the SHG is generally about 30 to 40%, the power of the light converted by the SHG element is considerably smaller than the power o...

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Problems solved by technology

And, if such residual fundamental wave light is directly returned to the fundamental wave laser light source, the power of the fundamental wave laser light source may be reduced and become unstable, so it is necessary not to return the remaining fundamental wave light to the light source.

Therefore, it is possible to increase the size of the optical system

In addition, since the length of the optical path becomes longer and the number of passes through optical elements increases, light loss may also occur

[0007] Furthermore, in the laser light source device described in Patent Document 1, in order to combine the first SHG light and the second SHG light, the polarization directions are in a state different from each other by 90°, so the output light has two types of polarization. Combining light, therefore, in the case where the laser light source device described in Patent Document 1 is considered to be used in combination with a polarization control device (such as a liquid crystal device) that can only use one type of polarized light, if If there is no configuration for aligning the polarization directions of the first SHG light and the second SHG light, only one SHG light can be used

[0008] That is, in the laser light source device described in Patent Document 1, although the power drop of the output light can be suppressed to some extent, and a stable output can be obtained, the utilization efficiency of the light has not been greatly improved.

In particular, when used in combination with a polarization-controlling device, there is a possibility that the utilization efficiency of light may not be improved at all.

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